This application relates generally to gas turbine engines and, more particularly, to methods and apparatus for assembling gas turbine engine rotor assemblies.
At least some known rotor assemblies include at least one row of circumferentially-spaced rotor blades, which are known as buckets in some applications. Each rotor blade includes an airfoil that includes a pressure side and a suction side connected together at leading and trailing edges. Each airfoil extends radially outward from a rotor blade platform. Each rotor blade also includes a dovetail that extends radially inward from a shank extending between the platform and the dovetail, and is used to mount the rotor blade within the rotor assembly to a rotor disk or spool. At least some known blades are hollow and include an internal cooling cavity that is defined at least partially by the airfoil, platform, shank, and dovetail.
During operation, a clearance between circumferentially-adjacent blades with a row of blades, may cause a platform seal pin positioned between each blade to bind during initial engine operations and/or during transient operations. Such binding may cause the platform seal pin to deform, may induce cracking within the platform, and/or may cause the seal between the shank area of the blade and the hot gas path to become ineffective. An increase in the sealing effectiveness may increase the life of the blade by facilitating minimizing thermal stresses. Accordingly, within at least some known gas turbine engines, cylindrical pins, machined to mate with a corresponding notch formed in the end cover plates of the blade have been used to facilitate reducing binding of the pins. However, such pins have also been shown to bind in operation.